Effects of dietary supplementation of meat-type quail breeders with guanidinoacetic acid on their reproductive parameters and progeny performance.

This study was conducted to assess the effect of dietary supplementation of meat-type quail breeders with guanidinoacetic acid (GAA) on their reproductive parameters and progeny performance. Two hundred forty meat-type quails at 25 wk of age were distributed in a completely randomized design with 5 treatments and 8 replicates of 6 birds each. The treatments consisted of 5 dietary levels of GAA (0.00, 0.06, 0.12, 0.18, and 0.24%). The progenies from quail breeders were housed according to breeder treatments and fed a conventional diet based on corn and soybean meal without GAA supplementation. Dietary GAA levels did not affect (P > 0.05) the productivity of meat-type quail breeders, although the concentration of guanidinic compounds (creatine, GAA, and creatinine) in the eggs from the breeders increased linearly (P < 0.05) according to the increase in dietary GAA levels. The number of spermatozoa present in the vitelline membrane was not affected (P > 0.05) by the treatments, but there was a quadratic effect (P < 0.05) of the levels of GAA on fertility, embryonic mortality, and egg hatchability, with the best results estimated at 0.13, 0.15, and 0.14% GAA, respectively. The creatine levels of the pectoral muscle in newborn quails showed a quadratic effect (P ≤ 0.07), and the dietary GAA level of 0.11% was estimated to maximize the muscular creatine level in the progeny. There was a quadratic effect (P < 0.05) of GAA levels on weight gain and feed conversion of progeny at 35 d of age with an optimization point of 0.14% GAA for these variables. Dietary GAA supplementation of meat-type quail breeders increases the availability of creatine in eggs and muscle of progeny, which results in better reproductive parameters and better postnatal progeny performance.

Amino acid utilization by the hindlimb of warmblood horses at rest and following low intensity exercise.

BACKGROUND: In particular branched-chain amino acids might limit muscle protein loss in pathological conditions. Little is known on basic amino acid utilization of muscle in horses. OBJECTIVE: To assess amino acid utilization by the hindlimb of horses at rest and following low intensity exercise. ANIMALS & METHODS: Amino acid uptake by the hindlimb was investigated using the arteriovenous difference technique. Blood from six warmblood mares (mean age 12 ± 3 (SD) years and weighing 538 ± 39 kg) was collected simultaneously from the (transverse) facial artery and from the caudal vena cava. Food was withheld for 12 hours prior to exercise. Exercise comprised a standardized treadmill protocol consisting of 5 minutes of walk, 20 minutes of trot, and thereafter another 5 minutes of walk. Amino acids were determined quantitatively by means of anion exchange chromatography. Statistical analysis was performed using a general linear mixed model. RESULTS: Amino acids with the largest average extraction at rest were citrulline (11.1 ± 9%), cystine (8.3 ± 36%), serine (7.9 ± 11%), and leucine (5.9 ± 9%). Of the 25 amino acids studied, none showed a significant difference following exercise. Glycine (485 ± 65 µmol/L), glutamine (281 ± 40 µmol/L), valine (183 ± 26 µmol/L), and serine (165 ± 22 µmol/L) showed highest plasma concentrations. The average extraction for α-aminobutyric acid at rest was 18.2 ± 26%. Arterial plasma citrulline concentration was higher than venously. CONCLUSION: Citrulline, cystine, serine, and leucine might be regarded as most important amino acids at rest in warmblood mares. CLINICAL IMPORTANCE: Further investigation is necessary into the specific role of leucine supplementation to preserve or restore body protein in horses.

Characterization of bovine neutrophil gelatinase-associated lipocalin.

A protein of relative molecular mass of approximately 25,000 was purified from bovine colostrum by cation-exchange and size-exclusion chromatography. The N-terminus of the protein matched the sequence predicted by the National Center for Biotechnology Information for the bovine homolog of human neutrophil gelatinase-associated lipocalin, a glycoprotein of relative molecular mass 25,000 belonging to the family of lipocalins. The protein was further designated as bovine neutrophil gelatinase-associated lipocalin (bNGAL). Sodium dodecyl sulfate-PAGE of enzymically deglycosylated bNGAL indicated that the intact protein bears one N-linked glycan. Monosaccharide and mass spectrometric analyses of released N-linked carbohydrates revealed the presences of complex- and hybrid-type glycans, with galactose substituted with N-acetylgalactosamine. This substitution is typical for glycoproteins expressed in the bovine mammary gland. A specific ELISA revealed bNGAL concentrations in plasma and mature milk of about 0.05 and 1 microg/mL, respectively, whereas values as high as 51 microg/mL were measured in colostrum. Thus, we have isolated and characterized a novel bovine (milk) protein that is a new member of the lipocalin family.

Effects of dietary supplementation with sodium chloride on urinary relative supersaturation with calcium oxalate in healthy dogs.

OBJECTIVE: To evaluate the effect of dietary supplementation with sodium chloride (NaCl) on urinary calcium excretion, urine calcium concentration, and urinary relative supersaturation (RSS) with calcium oxalate (CaOx). ANIMALS: 6 adult female healthy Beagles. PROCEDURE: By use of a crossover study design, a canned diet designed to decrease CaOx urolith recurrence with and without supplemental NaCl (i.e., 1.2% and 0.24% sodium on a dry-matter basis, respectively) was fed to dogs for 6 weeks. Every 14 days, 24-hour urine samples were collected. Concentrations of lithogenic substances and urine pH were used to calculate values of urinary RSS with CaOx. RESULTS: When dogs consumed a diet supplemented with NaCl, 24-hour urine volume and 24-hour urine calcium excretion increased. Dietary supplementation with NaCl was not associated with a change in urine calcium concentration. However, urine oxalate acid concentrations and values of urinary RSS with CaOx were significantly lower after feeding the NaCI-supplemented diet for 28 days. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary supplementation with NaCl in a urolith-prevention diet decreased the propensity for CaOx crystallization in the urine of healthy adult Beagles. However, until long-term studies evaluating the efficacy and safety of dietary supplementation with NaCl in dogs with CaOx urolithiasis are preformed, we suggest that dietary supplementation with NaCl be used cautiously.

Can betaine partially replace or enhance the effect of methionine by improving broiler growth and carcase characteristics?

1. Growth rates and carcase characteristics were measured in male broiler chickens fed on a control diet deficient in methionine (c. 2.8 g/kg methionine) or a series of diets containing graded levels of betaine or DL-methionine or both additives. 2. We aimed to answer 2 main questions. First, can betaine replace part of the methionine in a broiler ration? Secondly is there a synergism between methionine and betaine? 3. Birds given the control diet or that supplemented only with betaine ate less, grew more slowly, had higher food convension ratio (FCR) and varied more in mass at 42 d than birds fed diets with DL-methionine. Adding 1.2 g/kg DL-methionine to the control ration produced the heaviest birds at 42 d (2500 g) with the 2nd heaviest breast muscle (366 g). 4. After correcting for treatment differences in body mass (analysis of convariance), birds fed on the control diet and the diet supplemented with betaine only, had relatively lighter breast muscles but relatively heavier abdominal fat pads than those of birds given diets supplemented with DL-methionine. However, adding betaine to diets containing added methionine further improved the relative breast muscle yield. 5. After correcting for differences in body mass between treatments, birds fed on diets containing most methionine had lighter viscera than birds fed diets deficient in methionine. This demonstrated gut plasticity, suggesting that the viscera enlarged to sequester methionine from low-methionine diets. 6. Our data refute the hypothesis that betaine can substitute for methionine in broilers fed diets that are marginally deficient in methionine plus cystine. However, betaine may improve carcase composition, especially breast meat yield.

Purification of bovine urinary beta2-microglobulin and its biochemical characteristics.

In this study, bovine beta2-m was purified from urine by ion-exchange chromatography and gel chromatography, and the characteristics were compared with those of colostral beta2-m by the immunological reactivity, isoelectric points, peptide map, and amino acid sequence. The characteristics of purified urinary beta2-m were consistent with those of the colostral beta2-m. The urinary and colostral beta2-m possessed the same polypeptide chain consisting of 98 amino acids, and its molecular weight is 11.8 kDa. Furthermore, four isoforms of beta2-m were found. The isoelectric points were different from each other.

Response of broiler chickens to microbial phytase supplementation as influenced by dietary phytic acid and non-phytate phosphorous levels. II. Effects on apparent metabolisable energy, nutrient digestibility and nutrient retention.

1. Male broilers (n=900) were fed on wheat-sorghum-soyabean meal based diets containing 3 concentrations of phytic acid (10.4, 13.2 and 15.7 g/kg; equivalent to 2.9, 3.7 and 4.4 g/kg phytate P), 2 concentrations of non-phytate (or available) phosphorus (2.3 and 4.5 g/kg) and 3 concentrations of microbial phytase (0, 400 and 800 FTU/kg) from day 7 to 25 post-hatch. The dietary concentrations of phytic acid were manipulated by the inclusion of rice pollards. All diets contained celite (20 g/kg) as a source of acid-insoluble ash. 2. The apparent metabolisable energy (AME) concentrations of the diets were determined using a classical total collection procedure during the 3rd week of the trial. On d 25, digesta from the terminal ileum were collected and analysed for phosphorus, nitrogen and amino acids. Nutrient digestibilities were calculated using acid-insoluble ash as the indigestible marker. 2. Ileal digestibilities of nitrogen and essential amino acids were negatively influenced by increasing dietary levels of phytic acid but these negative effects were overcome by the addition of phytase. 3. Supplemental phytase increased AME, ileal digestibilities of phosphorus, nitrogen and amino acids and the retention of dry matter, phosphorus and nitrogen in broilers. There were no differences in the phytase responses between additions of 400 and 800 FTU/kg. 4. The responses in all variables, except AME, were greater in low non-phytate phosphorus diets. 5. In the case of AME, the response to added phytase was greater in adequate non-phytate phosphorus diets. Supplemental phytase increased AME values from 13.36 to 13.54 MJ/kg dry matter in low non-phytate phosphorus diets and from 12.66 to 13.38 MJ/kg dry matter in adequate non-phytate phosphorus diets.

Effects of dietary fat type, pentosan level and xylanase supplementation on digestibility of nutrients and metabolizability of energy in male broilers.

A complete two by two by four factorial design was used to examine the main effects of dietary fat type (10% soya oil or 10% beef tallow), xylanase supplementation (with or without Avizyme 1300 at 1 g/kg diet) and pentosan level (7.7 g/kg, 11.0 g/kg, 14.3 g/kg and 17.6 g/kg soluble pentosans, respectively, by varying wheat/rye proportions) as well as their interactions on intestinal chyme conditions, nutrient digestibility and nutrient utilization in male broilers. Nutrient digestibilities for the total digestive tract and at various sites of small intestine were measured during the period from day 18 to 20 of age and at day 21 of age, respectively, using a marker technique. Jejunal and ileal supernatant viscosity increased in an exponential manner as dietary pentosan concentration was increased. This increase was more pronounced in tallow fed birds but was also found in enzyme treated groups albeit at a much lower level. Xylanase activity was still detectable in the ileum of birds fed enzyme supplemented diets but its activity was found to decrease as dietary pentosan content increased. Digestibility of crude protein and that of some amino acids at the terminal ileum was decreased as dietary pentosan content was increased and significantly improved by xylanase addition. No fat effect and no interactions were detected at this site. In contrast, measurements made over the whole gastrointestinal tract showed significantly lower protein and amino acid digestibility values for tallow fed birds, and significant higher enzyme effects especially in diets with higher pentosan concentrations. Nitrogen-corrected apparent metabolizable energy (AMEN) content and net protein utilization decreased with increasing dietary pentosan content and were significantly improved by xylanase addition and were lower in tallow fed birds. Again, xylanase effects were found to be more pronounced for tallow fed birds and at higher pentosan concentrations.

Order of amino acid limitation in meat and bone meal.

Three experiments were conducted to determine the order of amino acid (AA) limitation in meat and bone meal (MBM) using AA addition and deletion assays. In two addition assays, various individual and combined additions of eight AA were made to semipurified basal diets containing 16% protein solely from a MBM. The two MBM had previously been determined to vary greatly in protein quality. In the deletion assay, a semipurified basal diet containing 13.5% CP provided solely by MBM was supplemented with L-Thr, L-Val, DL-Met, L-Leu, L-Ile, L-Phe, L-Tyr, L-Lys-HCl, L-His, and L-Trp to fulfill the Illinois Ideal Protein or AA pattern on a digestible basis. Each AA was then deleted individually from the basal diet, and the effect of its deletion on growth performance was assessed. In both addition assays, supplementation of the MBM basal diet with Trp and Cys together yielded a large increase in growth performance, whereas supplementation with these AA individually had no effect. These results indicated that Trp and sulfur AA (with a primary need for Cys) were equally first limiting in the MBM. The order of limitation for the other AA was unclear. The results of the deletion assay showed that deletion of Trp, Thr, Phe + Tyr, Ile, Met, Lys, Val, or His significantly depressed growth performance. The results of the combined addition and deletion experiments indicated that the order of AA limitation in MBM was 1) Trp and sulfur AA, 2) Thr, 3) Ile and Phe + Tyr, 4) Met, 5) Lys, and 6) Val and His. The deletion assay using diets formulated on an ideal protein basis was more effective than the addition assay for determining the order of AA limitation in MBM.

Purification and characterization of IgG1 and IgG2 from buffalo (Bubalus bubalis) serum and colostrum.

Buffalo IgG1 and IgG2 were purified from serum and colostrum using salt precipitation, dialysis, gel filtration and ion-exchange chromatography. Their purity was monitored by immunodiffusion and immunoelectrophoresis using anti-heavy chain specific sera and SDS-PAGE. Selective binding of IgG2 to protein-A was used to remove IgG2 from IgG1 preparations. The IgG1 and IgG2 had a molecular mass (Mr) of 162.0 and 161.5 kD, respectively and were found to consist of heavy (H) and light (L) chains. The H and L chains had Mr of 58 and 24 kD, respectively. Reduction-alkylation followed by gel filtration was used for the isolation of H and L chains. While intact H chains were obtained, the L chains appeared to be cleaved into 14 kD molecules and smaller fragments. The mean hexoses content of the serum IgG1 and IgG2 was 1.81 +/- 0.02% and 0.70 +/- 0.02%, respectively. The corresponding values for colostral IgG1 and IgG2 were 1.76 +/- 0.01% and 0.78 +/- 0.08%. Both the IgG subclasses activated homologous complement. These results suggest that buffalo and cattle IgG subclasses have many common characteristics and minor differences.